RepRap and Fab@Home are doing a great job to build an open-source solution to get a cheap fabbing solution for everybody, each one at various stage of production, each one with amazing ideas to continue the adventure?

Yesterday, it was proposed to build a bridge between the 2 communities, mainly because RepRap members need some parts to build first Darwin machines (which would be able to replicate themselves after), and Fab@Home might be able to produce these parts quickly. That’s the beginning of a faster way for everybody to generate more ideas:

At last, I’ve just finished testing the PowerComms card for our Darwin RepRap machine.
This is the summary of differents tasks during this process.

Getting PowerComms card

Zach has made an excellent job with pushing difficult Darwin parts on a web-shop.
It’s simple and really faster than doing your own PCB cards, but supplies are limited, so I prefer to order parts step by step to give priority to people well more advanced than me in their RepRap building.

Finding componants

I’ve never order any electronic componants on the web, and when I tried to do so on RadioSpares, it was so complicated I preferred to look for help.
After a week, I went to this little electronic shop – Le Comptoir du Languedoc – in the middle of Toulouse, and everything was ready in 10 minutes 🙂

Soldering componants

Looking for a power supply

It’s time of the century when you’ll find lots of people with dead computers at home, time to use their spare parts. After SMS-spamming all of my toulousian phone directory, Kortex answered first to the announce, and the power supply was retrieved the day after.

Switching on the power supply

Most of ATX power supply you’ll find won’t have a switch on them, this switch used to be connected on the computer motherboard.
You can easily make one yourself. For this, I used an old lamp switch, and connect 2 wires between the green wire and one of the black wire on the big pin plug.

Mac USB Serial connector

I’ve been a bit lost at first with this usbserial cable, a unknown brand one. After connecting it to an ubuntu computer, it was detected as a PL-2303 chipset.
After that, you just need to install one of the PL-2303 drivers for your Mac, and restart the computer.
Just verify you’ve got this file after reboot: /dev/cu.usbserial

Testing card

Open iTerm (or another terminal)

sudo minicom -s

Serial Port Setup

A – Serial Device : /dev/cu.usbserial

E – Bps/Par/Bits : 19200 8N1

F – Hardware Flow Control : No

G – Software Flow Control : No

Save setup as dfl

Connect the usbserial cable, place a wire between Tx and Rx (pin 13 and 14 on max232 chip), and open minicom. If you type on your keyboard, something should appear on the terminal.

Remove the wire between Tx and Rx, verify nothing appear in your minicom terminal when you type.

Connect the power to the PowerComms card anb switch on the power supply. If you type something in the minicom terminal, it should appear.

Getting help

RepRap wiki and forums are a big place for information, you should definitely use them in case of problem with your PowerComms card: